Method of making 104-106 r.o.n. leaded gasoline



Oct. 3,

W. W. HAMILTON METHOD OF MAKING 104-106 R.O.N. LEADED GASOLINE Filed Oct. 1, 1959 2 Sheets-Sheet 1 25 N'C5'300F. ER NOphfhCi (A) (Second Frocfion) 24; I 26 9 8 I8 To Refinery w 17 Fuel Hg-Recycle '5 C 390 gas 5 EE.F. g 5 14 m Feed VVV 3 I 9 o O 2 f g 3: 4 g, '5 2 E 2 5 '5; 3 g

3 rs |o| I i- |2 j I (Third Fraction) 54 300-390E Nuph'rho(B) 55% 5 s28 Low-Press. H -Recycie Gas 7 in y 36 74 7s H 99 I02 I00 (NinfhaFifih 79 Fraction) so I? g i 73 Q J A L Low 75 Pressure Reforming High Pressure H -conr'g Recycle gas 497 j 4? r\ r P High Pressure Reforming 50 FIG. l0 L/ INVENTOR. Wmron W.H mllron Lg 69 300 E El? Poroffins (0) (Sixth Frocfiom AGENT Oct. 3, 1961 w. w. HAMILTON 3,002,917

METHOD OF MAKING 104-106 R.O.N. LEADED GASOLINE Filed Oct. 1. 1959 2 Sheets-Sheet 2 2 (180'0510 Blend or Storage (Ninth Fraction) (First Fraction) 23 FRACTIONATOR -Lighter to R/efinery Fuel (Eighth Fraction) Low-Pressure Gas-Liquid Separator DEPROPANIZER C4to Recovery DEBUTANIZERJ FRACTIONATOR (FOURTH 85 FRACTION) AROMATIC GASOLINEUO4'IO6 R.O.N.+ 3CCTEL. High-Pressure A 2 Fmcilol'l) 2 Gus-Ll uid Sepqmioy {58 CG'i'AtOmCIfIC S (Fifth Fraction) 94 AGENT mtc The present invention relates to the manufacture of super-octane numbergasoline and, more particularly, to the manufacture of gasoline having a minimum research octane number (R.O.N.)+3cc. T.E.L. of at least about 104.

When a full range gasoline is reformed at low pressure over a suitable dehydrogenation-type catalyst, C and C parafiins are cyclicized to form aromatics. Higher boiling hydrocarbons are also converted to aromatics. However, at low pressures, polymers are also formed from high boiling components, resulting in polymer material boiling above the gasoline range and also in rapid deactivation of the catalyst due to coke deposition. The formation of polymers above the gasoline boiling range results in a loss in gasoline product yield. On the other hand, when a full range gasoline is reformed at high pressures, there is a tendency for hydrocracking of C and C hydrocarbons to form gas and C and C hydrocarbons. The present process eliminates the disadvantages inherent in both high and low pressure reforming, while taking benefit of the advantages of both types of reforming.

Illustrative of the method of the present invention is the flow sheet in the drawing comprising FIGURES 1a and 1b which provides for the treatment of a feed comprising a C to 420 F. end point naphtha or a C to 390 F. end point naphtha. The naphtha can be the fraction from straight run gasoline, the fraction from catalytically cracked gasoline, the fraction from thermally cracked gasoline or a mixture of fractions from two or more of straight run, catalytically cracked, and thermally cracked naphthas. Preferably, the feed is the C to about 380 to 390 F. end point naphtha, i.e., a fraction boiling between about 80 F. and about 380 to about 390 F.

The feed naphtha, e.g., C to 390 F. naphthas (B.R. about 80 F. to about 390 F.) is drawn from a source not shown through pipe 1 by pump 2 and discharged by pump 2 into pipe 3 at a pressure somewhat higher than the pressure in decontarninator 10. The feed naphtha flows through pipe 3 to coil 4 in heater or furnace 5. In coil 4 the feed naphtha is heated to a temperature of about 650 F. to about 850 F., i.e., about the temperature of hydrodecontaminator 10. For coil 4 the heated feed naphtha flows through pipe 6 to pipe 7.

In pipe 7 the heated feed naphtha at about the pressure existing in decontaminator is mixed with hydrogen-containing recycle gas delivered to pipe 7 by compressor 8 through conduit 9. From time to time or continuously hydrogen-containing gas flowing fromconduit 51 through conduits 5-3 and 101 and/or hydrogen-containing gas pumped by compressor 87 through conduit 88 to conduit 99 and by compressor 102 into conduit 5-3 are mixed with the heated feed naphtha in pipe 6. The hydrogen-containing gas is mixed with the feed naphtha in pipe 7 and/or pipe 6 in the proportion of about 100 to about 3000 standard cubic feet (s.c.f.) of hydrogen per barrel of feed naphtha to form the hydrodecontaminator charge mixture.

The charge mixture flows downwardly through decontaminator 10 in contact with contaminant insensitive hydrogenating catalyst at temperatures of about 600 F. to about 800 F. The presently preferred catalyst is a mixture of cobalt and molybdenum oxides supported on an alumina base. However, other contaminant-insensitive hydrogenating catalysts capable of converting contamipatented Oct. 3, 1961 nants such as organic sulfur and nitrogen compounds to volatile hydrogen derivatives of the contaminants can be used.

1 he decontaminator efiluent flows from decontaminator 10 through conduit 11 to cooler 12. In cooler 12 the temperature of the decontaminator eifluent is reduced to a temperature at which at the existing pressure C and C hydrocarbons are liquid. From cooler 12 the cooled decontaminator efliuent flows through conduit 13 to liquid-gas separator 14. In liquid-gas separator 14 the uncondensed portion of the decontaminator efiluent separates from the condensed portion of the decontaminator effluent and flows therefrom through conduit 15.

The uncondensed portion of the decontaminator efiiuent now designated recycle gas flows through conduit 15 to purifiers (not shown for simplicity) where the hydrogen derivatives of the contaminants such as hydrogen sulfide and ammonia are removed in well-known manner. From the purifiers (not shown) the purified recycle gas flows through conduit 18 to the suction side of compressor 8 and thence to pipe 7 as described hereinbefore. When desirable or necessary, a portion of the recycle gas can be vented to the refinery fuel system through conduit 16 under control of valve 17. When the amount of hydrogen produced in excess of the hydrogen required in either the low pressure or high pressure or the low pressure and the high pressure reforming units is sufficient to satisfy the requirements of the hydrodecontaminator, the hydrogen recycle to the hydrodecontaminator together With the purifiers mentioned hereinbefore can be omitted and the total or major portion of the hydrogen-containing gas from separator 14 vented to the refinery fuel system. In other words, when the amount of hydrogen produced in the high and/ or low pressure reforming units in excess of the requirements of the reforming units is sufiicient the excess hydrogen can be used on a once through basis or mixed with the hydrodecontaminator recycle gas in amounts to reduce the concentration of hydrogen derivatives of the contaminants to innocuous concentrations thus making it possible to omit the purifiers mentioned but not shown.

The liquid portion of the decontaminator efiiuent flows from separator 14 through pipe 19. In pipe 19 the liquid decontaminator efiiuent is mixed with the C overhead from fractionator 93 flowing therefrom through pipe 63. The liquid decontaminator efliuent and added C overhead flow through pipe 19 to deisopentanizer 20.

In deisopentanizer 20 the iso-pentanes are taken overhead through pipe 21 to storage, blending and the like. A bottoms fraction boiling above about F. flows from deisopentanizer 20 through pipe 22 to fractionator 23 In fractionator 23 an overhead having an end point of about 300 F. and comprising normal pentane and higher boiling hydrocarbons is drawn through pipe 24 by pump 25. Pump 25 discharges the n-C -300 F. end point naphtha into pipe 26 through which the n-C -300 F. end point naphtha designated fraction A, flows to pipe 27. A bottoms fraction designated fraction B is drawn from fractionator 23 through pipe 28 by pump 29 and discharged into pipe 30. This fraction generally has a boiling range of about 300 F. to about 390 F.

The bottoms from fractionator 23, i.e., fraction B, flows through pipe 28 to pump 29 which discharges fraction B into pipe 30 at a pressure of about 350 to about 1000 p.s.i.g. dependent upon the pressure in reactor 34 (H In pipe 30 fraction B is mixed with hydrogen-containing recycle gas flowing from compressor 48 through conduits 49 and 50. The recycle gas contains at least 25 percent and preferably about 90 percent hydrogen. The recycle gas, R is mixed with fraction B in the ratio of about 1 to about mols of hydrogen per mol of fraction B to form a high pressure charge mixture.

The high pressure charge mixture flows through pipe to coil 31 in furnace 32. In coil 31 the high pressure charge mixture is heated to reaction temperature within the range of about 850 F. to about 1000 F. From coil 31 the heated high pressure charge mixture flows through conduit 33 to high pressure reactor 34 (H In reactor 34 a reforming catalyst, preferably a platinum group metal reforming catalyst, e. g., containing about 0.1 to about 2.0 percent platinum group metal on a support such as alumina or silica or silica and alumina, and preferably as a static bed, is brought into contact with the high pressure charge mixture. The reaction products flow from reactor 34 through conduit 35 to coil 36 in furnace or heater 32. In coil 36 the efiluent from reactor 34 is reheated to reaction temperature within the range of about 850 F-about 1000 F. From coil 36 the reheated efiiuent from reactor 34 flows through conduit 37 to second stage high pressure reactor 38 (H In high pressure second stage reactor 38 the reheated effluent from reactor 34 is contacted With the same or a diiferent particle-form reforming catalyst and preferably with a platinum group metal reforming catalyst comprising 0.1 to 2.0 percent platinum on an alumina or silica or silica-aluminum support. The effluent from reactor 38 flows through conduit 39 to coil 40 in furnace 32. In coil 40 the effluent from second stage reactor 38 is reheated to reaction temperature Within the range of about 850 F. to about 1000 F. The reheated second stage reactor effluent flows from coil 40 through conduit 41 to third stage reactor 42 (H In third stage reactor 42 the reheated second stage effiuent is contacted with a particle-form solid reforming catalyst. The third stage reforming catalyst can be the same as or different from the first and second stage reforming catalysts. Presently, it is preferred to use a platinum group metal reforming catalyst comprising about 0.1 to about 2.0 percent platinum on a support such as alumina or silica or silica-alumina. From third stage reactor 42 the third stage efiiuent flows through conduit 43 to cooler 44 where the temperature of the third stage effiuent is lowered to that at which, under the existing pressure, the C and heavier hydrocarbons are condensed. The cooled third stage effiuent flows from cooler 44 through conduit 45 to gas-liquid separator 46.

. In gas-liquid separator'46 the uncondensed portion of the cooled third stage efliuent separates from the condensed portion. The separated uncondensed portion of the third stage effluent, designated high pressure recycle gas, flows from separator 46 through conduit 47 to the suction side of compressor 48. In compressor 48 the high pressure recycle gas is compressed to a pressure somewhat higher than that of reactor 34, say about to about 75 p.s.i. higher than the pressure existing 'in reactor 34. Compressor 48 discharges the re-compressed high pressure recycle gas into conduit 49. The recompressed high pressure recycle gas flows through conduit 49 to conduit 50 and thence to pipe 30.

All or a portion of the make-gas, i.e., gas in excess of that required in reactors 34, 38 and 42 to maintain the coke deposited on the catalyst at a tolerable level is bled from conduit 49 through conduit '51 under control of valve 52. The high pressure recycle gas flows through conduit 51 to conduit 53 and thence to pipe 6. Any high pressure recycle gas flowing in conduit 53 in excess of that required in hydrodecontarninator 10 can be transferred to other operations requiring hydrogen through conduit 54 under control of valve 55.

Returning to high pressure gas-liquid separator 46; the condensed portion of the third stage efiiuent flows from separator 46 through pipe 56 to debutanizer 57. In debutanizer 57 an overhead comprising C and lighter hydrocarbons is taken through pipe 58 to pipe 59.

The debutanized bottoms flows from debutanizer 57 through pipe 60 to depentanizer 61.

In depentanizer 61 an overhead comprising C hydrocarbons flows through pipe 62 to pipe 63 where the overhead mixes with the overhead of fractionator 93. The mixture flows through pipe 63 to pipe =19 and thence mixed with the condensate from separator 14 flows to deisopentanizer 20.

A bottoms comprising C and heavier hydrocarbons flows from depentanizer 61 through pipe 64 to fractionator 65. In fractionator 65 a fraction predominantly comprising substantially non-aromatic hydrocarbons boiling below 320 F. is taken overhead through pipe 66. All or part of the non-aromatic overhead can flow through pipe 67 to the suction side of pump 68 or all or a part can be diverted through pipe 71 under control of valve 70 to use as jet fuel per se or for blending to jet fuel. This overhead is a particularly desirable component of jet fuel because of the low aromatic content thereof.

Pump 68 discharges the substantially, non-aromatic overhead into pipe 69 through which the substantially non-aromatic overhead, designated 300 E.P. paraffins, flows to pipe 27.

Returning to fractionator 23; as described hereinbefore, an overhead comprising normal C to 300 F. end point naphtha is drawn as overhead from fractionator 23 through pipe 24 by pump 25. The n-C 300 F. naphtha (fraction A) is discharged by pump 25 into pipe 26 through which fraction A flows to pipe 27. The 300 E.P. paraffins, designated fraction C, flows through pipe 69 to pipe 27. In pipe 27 fractions A and C are mixed with low-pressure hydrogen containimg, recycle gas flowing from low-pressure, gas-liquid separator 70 as described hereinafter. The recycle gas and mixed fractions A and C are mixed in the proportion of about 1 to about 20; preferably about 4 to about 10 mols of hydrogen per mol of hydrocarbon in the mixed fractions A and C to form a low-pressure charge mixture.

The low-pressure charge mixture flows through pipe 27 to coil 71 in furnace 72. In coil 71 the low-pressure charge mixture is heated to a reaction temperature within the range of about 850 F. to about 1000 F. The heated low-pressure charge mixture flows from coil 71 through conduit 73 to first stage reactor 74 (L In first stage reactor 74 the low-pressure charge mixture is contacted with a reforming catalyst, preferably a reforming catalyst having marked capabilities for dehydrocyclicizing paraflins. It is presently preferred to use a platinum-group metal reforming catalyst which can be the same or unlike the platinum group metal reforming catalyst employed in the high-pressure reactors, e.g., a platinum group metal catalyst comprising about 0.1 to 2.0 percent platinum on a support such as alumina or silica or silica-alumina.

The first stage low pressure effluent flows from reactor 74 through conduit 75 to coil 76 in furnace 72. In coil 76the'first stage effluent is reheated to reaction temperature. The reheated first stage efiiuent flows from coil 76 through conduit 77 to second stage reactor 78 (L In second stage reactor 78 the reheated first stage efliuent is contacted with same or a different particleform reforming catalyst. Presently, it is preferred to use the same platinum group metal, particle-form catalyst in second stage reactor 78 as in first stage reactor 74.

From second stage reactor 78 the second stage effluent flows through the pipe 79 to coil '80 in furnace 72. In coil 80 the second stage efiiuent is reheated to reaction temperature within the range of about 850 F. to about 1000 F. From coil 80 the reheated second stage'efiluent flows through pipe 81 to third reactor 82 (L The third stage effluent flows from reactor 82 through conduit 83 to cooler '84 where the temperature of the third stage eficluent is reduced to one'at which C and heavier hydrocarbons are condensed under the existing pressure. The cooled third stage efliuent flows from cooler 84 throughconduit;85 to low-pressure gas-liquidseparator 70.

In low-pressure separator 70 the uncondensed portion of the cooled third stage effluent, designated low-pressure recycle gas, separates from the condensed portion of the cooled third stage eflluent and flows from separator 70 through conduit 86 to the suction side of lowpressure compressor 87. Low pressure compressor 87 discharges the recompressed low-pressure recycle gas into conduit 88. The recompressed low-pressure recycle gas flows through conduit 88 to pipe 27 as described hereinbefore.

The condensed portion of the cooled third stage eflluent flows from low-pressure gas-liquid separator 70 through pipe 89 to debutanizer 90. An overhead comprising C and lighter hydrocarbons is taken from debutanizer 90 through pipe 91 and mixed with the C and lighter hydrocarbons flowing from debutanizer 57 through pipe 58. The mixed C and lighter hydrocarbons flowing from pipes 58 and 91 flow though pipe 59 to depropanizer 95. In depropanizer 95 an overhead comprising C and lighter hydrocarbons is taken overhead through pipe 96 to the refinery fuel system. A bottoms comprising C hydrocarbons flows from depropanizer 95 through pipe 97 to butane recovery and use.

A bottoms fraction comprising C and heavier hydrocarbons flows from debutanizer 90 through pipe 92 to fractionator 93. In fractionator 93 an overhead comprising C hydrocarbons is taken as overhead through pipe 63. In pipe 63 the C hydrocarbons from fractionator 93 are mixed with the C hydrocarbons flowing as overhead through pipe 62 from depentanizer 61. The mixed C hydrocarbons flow through pipe 63 to pipe 19, and, mixed with the liquid portion of the hydrodecontaminator effluent, flow through pipe 19 to deisopentanizer 20.

A bottoms fraction comprising C and heavier aromatic hydrocarbons flows from the fractionator 93 through pipe 94 to means for admixing additives such as anti-knock material, anti-icers, etc., distribution, blending, storage, etc.

Returning now to fractionator 65 in the fractionating train of the high pressure unit; a bottoms fraction comprising aromatic hydrocarbons boiling at 320 F. and higher flows from fractionator 65 through pipe 98 to pipe 94 Where the 320 +F. aromatic hydrocarbons flowing through pipe 98 from fractionator 65 are mixed with the C and heavier aromatic hydrocarbons flowing through pipe 94 from fractionator 93 in the fractionating train of the low pressure unit. The mixture provides the superoctane gasoline of the present invention having a leaded octane number of about at least 104 to 106.

For convenience, the operating conditions of the various units are presented in the following tables:

TABLE III High-pressure reforming Broad Preferred Reactor Temp., F-.- 850-1, 000 900-980 Reactor Pressure, p.s.i. 350-1, 000 450-550 Big/naphtha mol ratio.. 1-10 6-8 Space Velocity, v./v./hr 0. 5-3. 0 1-2 Those skilled in the art will recognize that the hereinbefore described method is illustrative of a method for producing super-octane gasoline having a research octane number (+3 cc. T.E.L.) of 104 or greater and that the present method comprises pretreating a fraction of straight run or catalytically cracked or thermally cracked naphtha or a mixture of fractions of two or more of the aforesaid naphthas having an initial boiling point of about F. and an end boiling point; within the range of about 390 F. to about 420 F. and preferably having a boiling range of about 80 F. to about 390 F. and comprising generally C and heavier hydrocarbons or C and heavier hydrocarbons to remove contaminants such as sulfur and nitrogen as volatile hydrogen derivatives of the contaminants present. The effluent from the decontamination step is separated into (1) condensed hydrocarbons and (2) uncondensed hydrocarbons and hydrogen and hydrogen derivatives. The condensed effluent is fractionated to provide three fractions, to wit: a first or isopentane fraction, a second or normal C to about 300 F. naphtha (fraction A) and a third or 300 F.390 F. naphtha (fraction B). The 300 F.-390 F. naphtha (fraction B) is reformed at high pressure of about 350 to about 1000 p.s.i.g., the high pressure efiiuent separated into a condensed and uncondensed portion, the condensed portion of the high pressure eflluent fractionated into a fourth fraction comprising C and lighter hydrocarbons, a fifth fraction comprising C hydrocarbons, a sixth fraction comprising aliphatic C and heavier hydrocarbons (fraction C), and a seventh fraction comprising 320 F.+aromatics. The aliphatic C and heavier hydrocarbons (fraction C) are mixed with the n-C 300 F. fraction (fraction A) of the condensed decontaminator efiluent and reformed at low pressure of about 50-250 p.s.i.g. The low pressure effluent is separated into a condensed portion and an uncondensed portion. The condensed low pressure eflfluent is separated into an eighth fraction comprising C and lighter hydrocarbons, a ninth fraction comprising C hydrocarbons, and a tenth fraction comprising C +aromatics. The aforesaid first fraction (iso-C is blended with isopentanes from the fifth and ninth fractions and with the seventh and tenth fractions to provide a gasoline having an octane rating (Research+3 cc.) of at least 104. The aforesaid fourth and eighth fractions are fractionated to recover C hydrocarbons.

I claim:

1. A method of producing gasoline having a leaded octane number of at least 104 which comprises fractionating charge gasoline having an initial boiling point of about 80 F. and an end boiling point within the range of about 390 F. and about 420 F. to obtain (1) a first fraction comprising isopentanes, (2) a second fraction comprising normal pentane and heavier hydrocarbons and having an end point of about 300 F., and (3) a third fraction having an initial boiling point about the same as the end boiling point of the aforesaid second fraction and an end boiling point of about 420 F., reforming the aforesaid third fraction at high reaction pressure in excess of about 350 p.s.i.g. in the presence of hydrogen and particle-form reforming catalyst under reforming conditions to produce a reformate the hydrocarbons of which boiling above about 300 have a leaded octane number of at least 104 to obtain a high pressure reaction zone efliuent, separating said high pressure reaction zone effluent into high pressure recycle gas comprising C and lighter hydrocarbons and hydrogen, and a liquid eflluent, fractionating said liquid efiluent into a fourth fraction comprising C and lighter hydrocarbons, a fifth fraction comprising C hydrocarbons, a sixth fraction comprising C and heavier aliphatic hydrocarbons, and a seventh faction comprising aromatic hydrocarbons boiling above about 320 F., reforming the aforesaid second fraction comprising normal pentane and heavier hydrocarbons at low reaction pressure of about 50 to about 250 p.s.i.g. in the presence of hydrogen and particle-form solid reforming catalyst under reforming conditions to aromatize the C and heavier aliphatic hydrocarbons to aromatic hydrocarbons having a leaded octane number of at least 104 and to isomerize at least a part of the n-pentane to obtain a low pressure effluent, separating said lowv pressure effiuent into a low pressure recycle gas comprising C and lighter hydrocarbons and hydrogen, and a liquid effiuent, separating said liquid effluent into an eighth fraction comprising C and lighter hydrocarbons, a ninth fraction comprising C hydrocarhens, and a tenth fraction comprising C and heavier aromatic hydrocarbons having a leaded octane number of at least 104, and blending the aforesaid seventh fraction with the aforesaid tenth fraction and the isopentanes of the aforesaid fifth and ninth fractions to obtain a gasoline having a leaded octane number of at least 104.

2. The method of producing gasoline having a leaded octane number of at least 104 as set forth and described in claim 1 wherein the aforesaid fifth and ninth fractions are mixed with the charge gasoline before fractionating said charge gasoline and isopentane is recovered for blending.

3. The method of producing gasoline having a leaded octane number of at least 104 as set forth and described in claim 1 wherein at least a portion of the aforesaid sixth fraction is reformed at low pressures.

4. The method of producing gasoline having a leaded octane number of at least 104 as set forth and described in claim 1 wherein at least a portion of the aforesaid sixth fraction is recovered as a highly aliphatic jet fuel.

5. The method of producing gasoline having a leaded 8 octane number of at least 104 as set forth and described in claim 1 wherein the charge gasoline is hydrodecontaminated before fractionation.

6. The method of producing gasoline having a leaded octane number'of at least 104 as set forth and described in claim 1 wherein the reforming catalyst used in low pressure reforming has marked parafiin dehydrocyclicizing capabilities.

7. The method of producing gasoline having a leaded octane number of at least 104 as set forth in claim 1 wherein the catalyst employed for low pressure reforming is a platinum group metal catalyst having marked capabilities for dehydrocyclicizing paraflins and wherein the catalyst employed for high pressure reforming has marked capabilities for dehydrogenating naphthenes to aromatics.

8. The method of producing gasoline having a leaded octane number of at least 104 as set forth in claim 1 wherein substantially all of the'C hydrocarbons produced are recovered as a separate fraction, wherein substantially all of the isopentane is recovered as a separate fraction and wherein normal C is isomerized and heavier predominantly aliphatic hydrocarbons having an end boiling point of about 300 F. are dehydrocyclicized.

9. The method of producing gasoline having a leaded octane number of at least 104 as set forth in claim 1 wherein substantially all of the C hydrocarbons produced are recovered as a separate fraction, wherein substantially all of the isopentane is recovered as a separate fraction, wherein a portion of the C and heavier predominantly parafiinic hydrocarbons is recovered as jet fuel and the balance thereof is dehydrocyclicized and isomerized.

References Cited in the file of this patent UNITED STATES PATENTS 2,249,461 Diwoky July 15, 1941 2,304,187 Marschner Dec. 8, 1942 2,767,124 'Myers Oct. 16, 1956 2,905,619 Sutherland Sept. 22, 1959 UNITED :STATES PATENT. OFFICE CERTIFICATE OF CORRECTION Patent N00 s oozmn October a, 1961 Winton W. Hamilton It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5,, TABLE ll column 3 line 4 thereof for "608" read 6 8 Signed and sealed this 3rd day of April 19620 (SEAL) Attest:

ENEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

1. A METHOD OF PRODUCING GASOLINE HAVING A LEADED OCTANE NUMBER OF AT LEAST 104 WHICH COMPRISES FRACTIONATING CHARGE GASOLINE HAVING AN INITIAL BOILING POINT OF ABOUT 80*F. AND AN END BOILING POINT WITHIN THE RANGE OF ABOUT 390*F. AND ABOUT 420*F. TO OBTAIN (1) A FIRST FRACTION COMPRISING ISOPENTANES, (2) A SECOND FRACTION COMPRISING NORMAL PENTANE AND HEAVIER HYDROCARBONS AND HAVING AN END POINT OF ABOUT 300*F. AND (3) A THIRD FRACTION HAVING AN INITIAL BOILING POINT ABOUT THE SAME AS THE END BOILING POINT OF THE AFORESAID SECOND FRACTION AND AN END BOILING POINT OF ABOUT 420* F., REFORMING THE AFORESAID THIRD FRACTION AT HIGH REACTION PRESSURE IN EXCESS OF ABOUT 350 P.S.I.G. IN THE PRESENCE OF HYDROGEN AND PARTICLE-FORM REFORMING CATALYST UNDER REFORMING CONDITIONS TO PRODUCE A REFORMATE THE HYDROCARBONS OF WHICH BOILING ABOVE ABOUT 300*F. HAVE A LEADED OCTANE NUMBER OF AT LEAST 104 TO OBTAIN A HIGH PRESSURE REACTION ZONE EFFLUENT, SEPARATING SAID HIGH PRESSURE REACTION ZONE EFFLUENT INTO HIGH PRESSURE RECYCLE GAS COMPRISING C3 AND LIGHTER HYDROCARBONS AND HYDROGEN, AND A LIQUID EFFLUENT, FRACTIONATING SAID LIQUID EFFLUENT INTO A FOURTH FRACTION COMPRISING C4 AND LIGHTER HYDROCARBONS, A FIFTH FRACTION COMPRISING C5 HYDROCARBONS, A SIXTH FRACTION COMPRISING C6 AND HEAVIER ALIPHATIC HYDROCARBONS, AND A SEVENTH FACTION COMPRISING AROMATIC HYDROCARBONS BOILING ABOVE ABOUT 320*F., REFORMING THE AFORESAID SECOND FRACTION COMPRISING NORMAL PENTANE AND HEAVIER HYDROCARBONS AT LOW REACTION PRESSURE OF ABOUT 50 TO ABOUT 250 P.S.I.G. IN THE PRESENCE OF HYDROGEN AND PARTICLE-FORM SOLID REFORMING CATALYST UNDER REFORMING CONDITIONS TO AROMATIZE THE C6 AND HEAVIER ALIPHATIC HYDROCARBONS TO AROMATIC HYDROCARBONS HAVING A LEADED OCTANE NUMBER OF AT LEAST 104 AND TO ISOMERIZE AT LEAST A PART OF THE N-PENTANE TO OBTAIN A LOW PRESSURE EFFLUENT, SEPARATING SAID LOW PRESSURE EFFLUENT INTO A LOW PRESSURE RECYCLE GAS COMPRISING C3 AND LIGHTER HYDROCARBONS AND HYDROGEN, AND A LIQUID EFFLUENT, SEPARATING SAID LIQUID EFFLUENT INTO AN EIGHTH FRACTION COMPRISING C4 AND LIGHTER HYDROCARBONS, A NINTH FRACTION COMPRISING C5 HYDROCARBONS, AND A TENTH FRACTION COMPRISING C6 AND HEAVIER AROMATIC HYDROCARBONS HAVING A LEADED OCTANE NUMBER OF AT LEAST 104, AND BLENDING THE AFORESAID SEVENTH FRACTION WITH THE AFORESAID TENTH FRACTION AND THE ISOPENTANES OF THE AFORESAID FIFTH AND NINTH FRACTIONS TO OBTAIN A GAOSLINE HAVING A LEADED OCTANE NUMBER OF AT LEAST
 104. 